The present invention relates to filter structure and more particularly to filter medium construction wherein the fibers of the filter medium are preselectively oriented in a unique fashion with respect to the fluid stream to be passed therethrough.
It is generally known to preselectively orient the fibers of a filter medium, attention being directed to U.S. Pat. No. 4,360,433, issued to B. Walker et. al. on Nov. 23, 1982, wherein a majority of compacted fibers of a tubular wall of filter medium are supported by a surrounding apertured sheet with the fibers being approximately parallel to one another in a circumferential direction about the central axis of the tubular wall. In U.S. Pat. No. 4,390,031, issued to R. M. Berger on Jun. 28, 1983, fibers of a tubular cigarette filter are oriented in an adjacent and overlapping relation to extend transverse the longitudinal axis of the tubular filter. In U.S. Pat. No. 4,593,706, issued to E. G. Preston et. al. on Jun. 10, 1986, also for tubular cigarette filters, broken fibers of irregular length are rolled and formed into filter rods. In U.S. Pat. No. 4,915,835, issued to Y. Barzuza on Apr. 10, 1990, adjacent fibers of liquid filter mediums are disposed in dual relationship with the line of the liquid flow to be treated--a portion of the fibers being substantially parallel to the line of liquid flow and a portion of the fibers being transverse the line of liquid flow. In U.S. Pat. No. 5,470,470, issued to J. C. Leyat on Nov. 28, 1995, a liquid filter of a compacted mass of substantially parallel elongate fibers are oriented axially in a cylindrical casing to extend in substantially parallel relation transverse to the line of flow of liquid to be treated. In U.S. Pat. No. 5,657,750, issued to L. Colman et. al. on Aug. 19, 1997, hollow fiber filter elements are utilized to separate gas passed transversely therethrough from a liquid/gas fluid. Further, in U.S. Pat. No. 5,695,487 issued to B. Cohen et. al. on Dec. 9, 1997, a pleated fibrous web of longitudinally extending fibers is utilized as a liquid absorbent material and fibrous materials with parallel and adjacent fibers have been commercially available from various U.S. distributors such as Fibercraft, Inc. of Tupelo, Miss., which company has been selling such materials for absorbents, mattress padding and furniture cushioning.
The present invention recognizing the availability of such fibrous materials, utilizes the same in a new and useful manner for gas treating filters which are straightforward and economical in both manufacture and assembly, and, which provide a unique filter and fibrous medium arrangement having an increased filtration efficiency and a reduced resistance to the gaseous streams to be treated. Furthermore, the fibrous filter medium arrangement of the present invention lends itself readily to various geometric configurations and to combinations with other filter mediums.
Various other features of the present invention will become obvious to one skilled in the art upon reading the disclosure set forth herein.